[RFC PATCH v1 04/18] x86: Add the Secure Memory Encryption cpu feature

Tom Lendacky
2016-04-26T22:45:54Z

Update the cpu features to include identifying and reporting on the
Secure Memory Encryption feature.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/include/asm/cpufeature.h | 1 +
arch/x86/include/asm/cpufeatures.h | 5 ++++-
arch/x86/kernel/cpu/scattered.c | 1 +
3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 07c942d..e27e352 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -27,6 +27,7 @@ enum cpuid_leafs
CPUID_6_EAX,
CPUID_8000_000A_EDX,
CPUID_7_ECX,
+ CPUID_8000_001F_EAX,
};

#ifdef CONFIG_X86_FEATURE_NAMES
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 47b5056..4aea205 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -12,7 +12,7 @@
/*
* Defines x86 CPU feature bits
*/
-#define NCAPINTS 17 /* N 32-bit words worth of info */
+#define NCAPINTS 18 /* N 32-bit words worth of info */
#define NBUGINTS 1 /* N 32-bit bug flags */

/*
@@ -282,6 +282,9 @@
#define X86_FEATURE_PKU (16*32+ 3) /* Protection Keys for Userspace */
#define X86_FEATURE_OSPKE (16*32+ 4) /* OS Protection Keys Enable */

+/* AMD SME Feature Identification, CPUID level 0x8000001f (eax), word 17 */
+#define X86_FEATURE_SME (17*32+ 0) /* Secure Memory Encryption support */
+
/*
* BUG word(s)
*/
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 8cb57df..d86d9a5 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -37,6 +37,7 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{ X86_FEATURE_HW_PSTATE, CR_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CR_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CR_EDX,11, 0x80000007, 0 },
+ { X86_FEATURE_SME, CR_EAX, 0, 0x8000001f, 0 },
{ 0, 0, 0, 0, 0 }
};